a) Field of the Invention
The present invention relates to a rearview mirror mounted outside a car and in which a mirror unit is pivotably supported on a mirror housing, such as a remote- or manually-controllable mirror, and more particularly to a car rearview mirror composed of a reduced number of parts.
b) Related Art Statement
Many car rearview mirrors that are mounted outside a car have so far been proposed. A typical one is disclosed in the U.S. Pat. No. 4,764,004.
As illustrated in FIG. 1, this prior-art car rearview mirror has a mirror unit A (composed of a mirror body B having a reflecting surface on the front side thereof, and a back plate C disposed at the rear side of the mirror body B) pivotably mounted directly to a mirror housing D or tiltably mounted to the mirror housing D by means of a power unit (not shown) which is remote-controlled to tilt or turn the mirror unit A vertically (about the horizontal axis of the mirror unit) and horizontally (about the vertical axis of the mirror unit).
More specifically, the mirror unit A has a hemispheric fixture E formed integrally at the center of the back plate C thereof. The hemispheric fixture E has a through-hole F formed in the center thereof. On the other hand, a hemispheric concave surface G is formed either directly on the mirror housing D or on the power unit fixed inside the mirror housing O, and a boss H is formed integrally at the center of the hemispheric concave surface G.
To assemble this rearview mirror, a hemispheric washer J having a through-hole I formed in the center thereof is put on the inner hemispheric concave surface of the fixture E, and then the boss H of the mirror housing D is passed through the holes F and I in the fixture E and hemispheric washer J, respectively, thereby applying the hemispheric convex surface of the fixture E of the mirror unit A to the hemispheric concave surface G of the mirror housing D. Next, a coil spring M is fitted onto the boss H, a plain washer K is put on the top end of the coil spring M, and a screw L is driven into the boss H from the free end of the latter, to thereby fix the plain washer K there and hold the coil spring M as compressed between the hemispheric washer J and plain washer K.
Namely, the coil spring M compressed between the hemispheric washer J and plain washer K works on the hemispheric washer J which in turn will force the outer hemispheric convex surface of the fixture E to the hemispheric concave surface G. Thus, the mirror unit A is pivotably held on the mirror housing D. The mirror unit A can be tilted relative to the mirror housing D by hand or by means of the power unit (not illustrated).
As known from the foregoing description, this prior-art rearview mirror uses many parts including the hemispheric washer J, plain washer K, screw L and coil spring M, in addition to the mirror unit A and mirror housing D.